Field of the Invention
The invention relates to a pressure sensor component that can be mounted on the component-mounting surface of a printed circuit board. The component comprises a chip carrier, preferably made from an electrically insulating material, which has an approximately flat chip carrier surface supporting a semiconductor chip with a pressure sensor. Electrode connections with a surface mountable configuration penetrate the chip carrier and are electrically connected to the semiconductor chip.
The use of surface mountable semiconductor component housings in an SMD (Surface Mounted Design) configuration renders it possible to make contact on a user printed circuit board in a cost-effective space-saving fashion. This also holds for sensor components used for pressure measurement. With this form of mounting, the component connections no longer plugged into holes in the printed circuit board as in the case of insertion mounting, but are mounted on connecting areas on the printed circuit board and soldered there. Components can be smaller for surface mounting than for insertion mounting, since hole and pad diameters of the printed circuit board no longer determine the pitch of the connections. Furthermore, holes required only for mounting on the printed circuit board are eliminated, it being possible for the holes still required only for through-plating to be executed as small as is technically possible. Since, in addition, it is also possible for the printed circuit board to be mounted on both sides, surface mounting can deliver a substantial saving in space and a considerable reduction in cost. A particularly small overall height of the electronic component results in this case when the electrode connections, which penetrate the chip carrier and are electrically connected to the semiconductor chip, are constructed in the form of pins which are led out of at least two sides of the chip carrier and are bent to form short rocker shaped connecting stubs and cut.
In order to measure pressures, the medium to be measured must be brought up to the sensor, or the pressure prevailing in the medium must be transmitted to the sensor. For this purpose, the pressure sensor is arranged in a component housing open on one side so that the sensitive chip surface of the pressure sensor can come directly into contact with the medium to be measured. There is the disadvantage with this configuration that the sensitive chip sensor, but also the other constituents of the pressure sensor component open on one side, are exposed to damaging environmental influences, resulting in the risk of corrosion of the constituents of the component which can lead as far as destruction of the component.
Patent Abstracts of Japan, Vol. 095, No. 008 (JP A 0 7113706) discloses a pressure sensor which has a silicon gel inside the housing. The component described is not suitable for SMD mounting. The housing is closed by means of a cover.